Organic electronics is an emerging field of technology which aims to realize low-cost and environmentally-friendly fabrication of electronic devices. This field has drawn many researchers' interest both from academia and industry, and has seen a remarkable evolution in the past few years. See, for example: Forrest, S. R., “The path to ubiquitous and low-cost organic electronic appliances on plastic”, Nature, vol. 428, pp. 911-918 (2004); and Katz, H. E., “Recent Advances in Semiconductor Performance and Printing Processes for Organic Transistor-Based Electronics”, Chem. Mater., Vol. 16, pp. 4748-4756 (2004); the entirety of each of which is hereby incorporated herein by reference.
Organic field effect transistors (“FETs”), for example, are potential alternatives to amorphous silicon transistors, and are useful for instance in relatively low-speed devices such as pixel drivers of active matrix displays and radio frequency identification. Background information is provided in: Gelnick G. H. et al., “Flexible active-matrix displays and shift registers based on solution-processed organic transistors”, Nature Mater., Vol. 3, pp. 106-110 (2004); and Kelley, T. W. et al., “Recent progress in organic electronics: Materials, devices, and processes”, Chem. Mater., Vol. 16, pp. 4412-4422 (2004), the entirety of each of which is hereby incorporated herein by reference.
Potential advantages to making organic FETs instead of silicon- or other inorganic-based transistors include the possibilities of large-area and low-temperature fabrication, which may help enable fabrication of electronics such as display drivers on flexible plastic substrates. Polymers such as poly(alkylthiophene), and small organic molecules such as pentacene, can potentially be used as the semiconductor in these devices.
Patterning of various active device components, such as electrodes, dielectrics and semiconductors, is one of the key desirable fabrication capabilities in forming useful circuits from organic FETs. For example, pixel driver FETs in a backlit matrix display could benefit from higher current dynamic range (on/off ratio), lower crosstalk among pixels, and higher transparency, as a result of patterned semiconductor films. Background information is provided in Kymissis, I., Dimitrakopoulos, C. D., and Purushothaman, S., “Patterning pentacene organic thin film transistors”, J. Vac. Sci. Technol. B, vol. 20, pp. 956-959 (2002), the entirety of which is hereby incorporated herein by reference.
Much work has been done to develop processes suitable for the fabrication of active electronic devices using organic semiconductors and dielectric materials. In one approach, an organic semiconductor was deposited onto an interlayer, and the resulting laminate of the semiconductor and interlayer was then transferred onto a receiving substrate, sandwiching the semiconductor as the middle layer. This approach did not enable the subsequent exposure of the semiconductor interface formed with the interlayer, which is desirable in some instances. In another approach, a semiconductor was deposited onto a release surface which then generated an explosive gas release to push the semiconductor onto a receiving substrate.
There accordingly is a continuing need for processes to enable the fabrication of active electronic devices comprising an organic semiconductor having an interface with an organic dielectric material.